The team did well in the last year, despite the fact that they moved to 4th place in the standings at the last moment, I think this is a good result. So what is happening to the team now I think it is clearly not because of the coach, there are problems in the team that do not depend on Ten Hag, as a coach he fulfils his function, there is no need to change him. Although lately I don't agree with his policy at all...
Manchester United didn't do well in the beginning of the season last year and they are doing the same this season. In the last two games they lost unexpectedly vs Crystal Palace in EPL and Galatasaray in Champions League. Defensive errors are unforgivable in such highly intense competitions and injuries couldn't be an excuse there.
Their next two games aren't that hard before returning again in Champions League and facing just next Manchester City. I am not very optimistic about them in Champions League nor vs City.
I understand, for the most part I agree with you, but I stated in my post the fact at the end of the season that things have more or less normalised. Injuries to players are something that the coach can't influence, so it's hard for me to say that in this case injuries don't play a role, they just directly influence it